CS240: Programming in C Lecture 1: Class overview. Cristina Nita-Rotaru Lecture 1/ Fall 2013 1 Why learn C (1) ! C is one of the foundations for CS: " Contains/applies principles from programming languages, computer architectures, operating systems, network communication, database, graphical user interface (GUI), graphics, image processing, parallel processing, multi-threads, real-time systems, device drivers, data acquisition, algorithms, numerical analysis, and computer game. Cristina Nita-Rotaru Lecture 1/ Fall 2013 4 What does this buy you? ! Understanding: understand better the interaction between machine and software: " “…teaches individuals how computers really work” " “…built a foundation you’ll be thankful for every 300+ level course ” Cristina Nita-Rotaru Lecture 1/ Fall 2013 5 Why learn C (2) ! C is the most commonly used programming language in industry. " Next two popular are Java and C++ " Language of systems programming: low-level control over the OS, networking, crypto operations, email, games, embedded systems have higher performance when written in C http://www.langpop.com Cristina Nita-Rotaru Lecture 1/ Fall 2013 6 What does this buy you? ! Helps you be as prepared as possible for a job: " Most of the employers want candidates to know multiple languages " Will prepare you better for a job interview " Gives you more opportunities within a company Cristina Nita-Rotaru Lecture 1/ Fall 2013 7 Why learn C (3) ! C is the base for almost all popular programming languages. ! Because of the performance and portability of C, almost all popular cross-platform programming languages and scripting languages, such as C++, Java, Python, Objective-C, Perl, Ruby, PHP, Lua, and Bash, are implemented in C and borrowed syntaxes and functions heavily from C. ! Almost all languages can interface with C and C++ to take advantage of a large volume of existing C/C++ libraries. Many of their toolkits, modules or packages are written using C or C++. Cristina Nita-Rotaru Lecture 1/ Fall 2013 8 What does this buy you? ! It will help you learn quickly other languages ! It will allow you to interface with many other languages Cristina Nita-Rotaru Lecture 1/ Fall 2013 9 Reference material ! The C Programming Language, Brian W. Kerninghan and Dennis M. Ritchie, 2nd Edition ! Lecture slides posted online Cristina Nita-Rotaru Lecture 1/ Fall 2013 23 How to study ! Read the book, reference material, slides, man pages ! Code each example from class, don’t just read it, code it ! Do the labs and projects ! Do the practice exercises from lectures ! Start small, then add functionality ! Make mistakes and observe output ! Make sure you always understand why it did not work and why the solution works Cristina Nita-Rotaru Lecture 1/ Fall 2013 26 Terminology ! What’s a computer? ! What is hardware/software ! What’s an algorithm ? ! What’s a program? ! What’s an operating system? ! What’s a programming language ? " Machine language " Assembly language " High-level language Cristina Nita-Rotaru Lecture 1/ Fall 2013 31 Computer architecture Mouse Memory Network Keyboard CPU Display Storage Cristina Nita-Rotaru Lecture 1/ Fall 2013 32 APPLICATIONS OPERATING SYSTEM HARDWARE Cristina Nita-Rotaru Lecture 1/ Fall 2013 33 OS Job ! Management of the processes and their access to resources " Memory " CPU access " I/O " Network " Other devices ! Interaction with the user " Graphic interface " Other devices Cristina Nita-Rotaru Lecture 1/ Fall 2013 34 Algorithm/Program ! Algorithm: procedure for solving a problem in finite steps ! Program: set of instructions to the CPU, stored in memory, read and executed by the CPU Cristina Nita-Rotaru Lecture 1/ Fall 2013 35 Machine and assembly language ! Machine language : binary information, specific to a CPU " How a CPU interprets data: e.g. how are memory addresses represented, how is an instruction coded, etc " This is the binary or executable code ! Assembly language: easier to write for people, using symbols, requires an assembler " Still need to think in terms of low level CPU steps " Still hardware-specific Cristina Nita-Rotaru Lecture 1/ Fall 2013 36 High-level language ! Closer to human language ! Needs a compiler to convert it to machine language ! One can write programs in many high-level languages for the same CPU ! More portable ! Examples: C, C++, C#, Objective C, Java, SmallTalk, also Cobol, Basic, Pascal … Cristina Nita-Rotaru Lecture 1/ Fall 2013 37 Readings for next lecture K&R Chapter 1: A tutorial introduction Cristina Nita-Rotaru Lecture 1/ Fall 2013 38 .